1. Field of the Invention
The present invention relates to a resist coating and developing processing apparatus for coating a substrate such as a semiconductor wafer and the like with a resist solution to form a resist film and for performing developing processing for the resist film on the substrate after exposure by an aligner.
2. Description of the Related Art
In a photolithography process of a semiconductor device, a semiconductor wafer is coated with a resist, a resist film formed by the coating is exposed in accordance with a predetermined circuit pattern, and the exposed pattern is developed, whereby a circuit pattern is formed on the resist film.
To perform such a series of processes, conventionally a resist coating and developing processing system has been used. Such a resist coating and developing processing system comprises: a processing station in which various processing units for performing various kinds of processing for coating and development for a wafer are multi-tiered; a cassette station, in which cassettes for housing a plurality of semiconductor wafers are mounted, for carrying the semiconductor wafers into the processing station one by one and carrying the semiconductor wafer after processing out of the processing station and housing it in a cassette; and an interface section for delivering the wafer to/from an aligner, disposed adjacent to the system, for exposing a resist film in a predetermined pattern, which are integrally provided.
In such a resist coating and developing processing system, wafers are taken out of the cassettes placed in the cassette station one by one and transferred to the processing station. The wafer is first subjected to hydrophobic processing in an adhesion processing unit and cooled in a cooling processing unit, and thereafter coated with a photoresist film in a resist coating unit and subjected to baking processing in a heat processing unit.
Thereafter, the semiconductor wafer is transferred to the aligner from the processing station via the interface section and the resist film is exposed in a predetermined pattern in the aligner. After exposure, the semiconductor wafer is transferred again to the processing station via the interface section. The exposed semiconductor wafer is first subjected to post-exposure bake processing in the heat processing unit and cooled, and thereafter coated with a developing solution in a developing processing unit, whereby the exposed pattern is developed. Then, the semiconductor wafer is subjected to post-bake processing in the heat processing unit and cooled, and thus a series of processes is completed. After the completion of the series of processes, the semiconductor wafer is transferred to the cassette station and housed in a wafer cassette.
In such a resist coating and developing processing system and aligner, the pressures therein are set higher than the pressure in the clean room in which the system and aligner are placed to prevent entry of particles and the like from the outside.
Recently, with high integration of semiconductor devices, it is demanded to make patterns more minute, and a chemically amplified resist is used as a resist capable of forming such minute patterns.
However, the chemically amplified resist is highly environment-dependent and susceptible to causing poor resolution with the existence of not only particles but also of alkaline components such as ammonia and the like and presents large ununiformity in line width due to changes in temperature and humidity.
Thus, in resist coating processing, developing processing, and exposure processing, it is necessary to exclude especially particles and alkaline components such as ammonia and the like thoroughly and it is also necessary to preclude changes in temperature and humidity as much as possible. Therefore, it is not enough only to set the pressures in the resist coating and developing processing system and aligner higher than the pressure in the clean room as described above.
An object of the present invention is to provide a resist coating and developing processing apparatus capable of effectively excluding influence of impurity components such as particles, alkaline components, and the like and changes in atmosphere such as temperature, humidity, and the like on processing.
To attain the above object, a first aspect of the present invention is a resist coating and developing processing apparatus comprising: a processing section in which a plurality of processing units for performing various kinds of processing for resist-coating and developing processing for a substrate are disposed; a carrying in/out section, including a mounting portion capable of mounting a substrate housing container for housing a plurality of substrates thereon, for carrying the substrate from the substrate housing container into the processing section and for housing the substrate carried out of the processing section in the substrate housing container; an interface section for receiving the substrate from the processing section and passing it to an aligner and for receiving the substrate after exposure from the aligner and passing it to the processing section; airflow forming means for forming flows of air from the tops of the carrying in/out section, processing section, and interface section toward the bottoms; and control means for controlling the airflow forming means, the processing section including draft openings communicating with the carrying in/out section and the interface section respectively, and the control means controlling the airflow forming means so that the pressure in the processing section becomes higher than the pressures in the carrying in/out section and in the interface section to form flows of air from the processing section into the carrying in/out section and the interface section.
According to the structure as above, the airflow forming means forms airflows from the tops of the carrying in/out section, processing section, and interface section toward the bottoms, and the control means controls the airflow forming means so that the pressure in the processing section becomes higher than the pressures in the carrying in/out section and in the interface section to form flows of air from the processing section into the carrying in/out section and the interface section, thereby preventing entry of air from the carrying in/out section and the interface section into the processing section and securely preventing entry of impurities into the processing section for performing resist-coating and developing processing which loathes entry of impurities and changes in atmosphere and changes in atmosphere in the processing section.
Further in the aforesaid resist coating and developing processing apparatus, the interface section includes a communicating opening communicating with the aligner and the control means controls the airflow forming means so that the pressure in the interface section becomes lower than the pressure in the aligner to thereby form a flow of air from the aligner into the interface section, thereby preventing entry of air into the aligner from which influence of temperature needs to be excluded to obtain a precise pattern.
In this case, it is preferable that the control means controls the airflow forming means so that the pressure in the processing section becomes lower than the pressure in the aligner. Thereby, entry of air from the processing section into the aligner which loathes entry of external atmosphere can be securely prevented. In such a structure, it is preferable to provide a draft opening of the processing section communicating with the interface section at a position higher than the communicating opening of the interface section communicating with the aligner. Thereby, the airflow control can be made easier.
As for the concrete structure of the airflow forming means, one including an air supply mechanism for supplying air from the tops of the carrying in/out section, processing section, and interface section and an exhaust mechanism for exhausting air from the respective bottoms can be shown. In this case, the control means can control the pressures of the carrying in/out section, processing section, and interface section by controlling the air supply mechanism and/or the exhaust mechanism.
Moreover, the air supply mechanism can be structured to include dampers provided at air introducing ports at the respective tops of the carrying in/out section, processing section, and interface section. In this case, the control means can control the degrees of opening of the dampers to control the pressures of the carrying in/out section, processing section, and interface section.
The exhaust mechanism can be structured to include slit dampers provided at the respective bottoms of the carrying in/out section, processing section, and interface section and exhaust fans provided under the slit dampers. In this case, the control means can control the pressures of the carrying in/out section, processing section, and interface section by controlling the degrees of opening of the slit dampers and/or the numbers of revolutions of the exhaust fans.
The processing section can be structured to include further a transfer path and a transfer apparatus, moving in the transfer path, for transferring the substrate to the plurality of processing units. In this case, the exhaust mechanism can exhaust air downward from the bottom of the transfer path.
The processing section can be structured to include thermal-system processing unit group composed of a plurality of thermal-system processing units for performing thermal processing for the substrate stacked in tiers and rotary-system processing unit group composed of coating processing units and/or developing processing units for performing processing while the substrate is rotated stacked in tiers. In this case, it is preferable that the air supply mechanism supplies air to the rotary-system processing unit group, and the thermal-system processing unit group and the transfer path separately and the control means controls the air supply mechanism so that the pressure in the rotary-system processing unit group becomes higher than the pressure in the transfer path and the thermal-system processing unit group. Thereby, entry of air from the transfer path and the thermal-system processing unit group into the rotary-system processing unit group for which the most precise management is required in the processing section can be prevented and entry of impurities into the rotary-system processing units for performing resist coating and developing processing and changes in the atmosphere can be further securely prevented.
The control means can be structured to control the pressures of the carrying in/out section, processing section, and interface section based on detected values of pressure sensors for detecting the respective pressures of the carrying in/out section, processing section, and interface section.
It is preferable to include further filters respectively provided at air introducing portions of the carrying in/out section, processing section, and interface section, for cleaning air. Thereby, processing atmosphere can be cleaned more highly.
Further, it is preferable to perform one of managing temperature, or temperature and humidity of air of the processing section, managing concentrations of air contamination of the carrying in/out section, processing section, and interface section, and managing ammonia concentrations of air of the processing section and interface section.
A second aspect of the present invention is a resist coating and developing processing apparatus comprising: a processing section in which a plurality of processing units for performing various kinds of processing for resist-coating and developing processing for a substrate are disposed; a carrying in/out section, including a mounting portion capable of mounting a substrate housing container for housing a plurality of substrates thereon, for carrying the substrate from the substrate housing container into the processing section and for housing the substrate carried out of the processing section in the substrate housing container; an interface section for receiving the substrate from the processing section and passing it to an aligner and for receiving the substrate after exposure from the aligner and passing it to the processing section; airflow forming means for forming flows of air from the tops of the carrying in/out section, processing section, and interface section toward the bottoms; and control means for controlling the airflow forming means, the processing section including a first and a second draft opening communicating with the carrying in/out section and the interface section respectively, and the control means controlling the airflow forming means to form flows of air with a strength not more than a first strength from the tops of the carrying in/out section, processing section, and interface section toward the bottoms when the resist coating and developing processing apparatus is processing the substrate, and to form flows of air with a second strength which exceeds the first strength from the tops of the carrying in/out section and processing section toward the bottoms in a predetermined case.
In the present invention, flows of air are formed with the second strength which exceeds the first strength from the tops of the carrying in/out section and processing section toward the bottoms during maintenance, for example, whereby particles which form during maintenance can be forcibly excluded from the carrying in/out section and the like.